XML Schema Reference

The notation Element

The notation element represents a notation as defined by the W3C XML Recommendation. A notation provides a mechanism for an XML validator to locate external programs or processing instructions. An XML validator does not intrinsically validate notations. However, during validation of a corresponding XML instance, a notation must exist for each reference from an element or attribute whose corresponding (structure) type is the built-in NOTATION datatype.

Each notation must specify a system attribute, a public attribute, or both. The value of a system attribute frequently identifies a file, which might be a program. There is no requirement that the file exists on the parsing machine, or that the file exists at all. The value of a public attribute frequently identifies an external HTTP address. This URI might likewise represent a document or a program such as an Active Server Page (ASP) or JavaServer Page (JSP).

    <xsd:notation name="companyLogo"
                  system="com/company/graphics/companyLogo"
                  public="http://www.company.com/graphics/companyLogo"
                  id="notation.companyLogo">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">
                Location of the corporate logo.
            </xsd:documentation>
        </xsd:annotation>
    </xsd:notation>

    <xsd:notation name="companyMascot"
                  system="com/company/graphics/companyMascot"
                  public="http://www.company.com/graphics/companyMascot"
                  id="notation.companyMascot">
        <xsd:annotation>
            <xsd:documentation xml:lang="en">
                Location of the corporate mascot.
            </xsd:documentation>
        </xsd:annotation>
    </xsd:notation>

Note that an element type may not directly reference a notation. An element type may only reference a derivation of NOTATION, which has enumerations. The value of each enumeration must be a notation.

    <xsd:element name="demoNotation">
        <xsd:simpleType>
            <xsd:restriction base="xsd:NOTATION">
                <xsd:enumeration value="companyLogo"/>
                <xsd:enumeration value="companyMascot"/>
            </xsd:restriction>
        </xsd:simpleType>
    </xsd:element>